Containers of various sorts including bottles and cans and jars, etc., are commonly filled with liquid type products in a production line by a rotary type piston filling machines. In general, containers arrive on a conveyor line and are successively applied onto a turret in underlying relation with a revolving piston type filler. The filler has a piston moving in an upright cylinder, and the piston is reciprocated upwardly and downwardly during revolving of the filler and turret so that the liquid product is drawn into the piston and is subsequently expelled from the piston into the container being filled. The amount of liquid product that is supplied into the container in the filling operation is measured by the magnitude of the piston movement in the cylinder, and the size of the cylinder.